Mu-conotoxin KIIIA of 18 aas. This toxin potently blocks rNav1.2/SCN2A
and rNav1.4/SCN4A but also moderately blocks rNav1.1/SCN1A,
rNav1.3/SCN3A, rNav1.5/SCN5A, mNav1.6/SCN8A, and rNav1.7/SCN9A. On
rNav1.2/SCN2A, it produces a block that is only partially reversible.
The block of SCN9A is modified when beta-subunits are coexpressed with
the alpha subunit (McArthur et al. 2011; Zhang et al. 2013).